One point of note - ice forms at 32 degrees F, but it doesn't stay there. The usual temp for most home freezers is 0F, so you can expect your ice to be closer to that temp range.
My practice is to use a water bath in my sink (I leave the water running and let it flow out and drain into the second basin) until my wort gets to around 100-120F, then drain the water and make an ice water bath. Once the wort gets to about 80 or so I add a frozen 20-ounce water bottle that has been sprayed down with Star-San right into the brew kettle. Each of these steps moves pretty quick, and I don't end up wasting any ice to cool something that could have been done just as easily with a water bath.